CVE-2026-12891 — MEDIUM (4.3)

Vulnerability Description

A flaw was found in the GStreamer gst-plugins-bad package. When processing a malformed H.266/VVC video stream with a crafted aspect ratio indicator value, the H.266 parser performs an out-of-bounds read of up to 8 bytes from adjacent memory. This flaw allows an attacker to craft a malicious H.266 video file or stream that, when processed by a GStreamer-based application, could leak limited memory contents through video metadata, potentially exposing sensitive information from the application's address space.

CVSS Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

LOW

Integrity

NONE

Availability

NONE

Affected Products

Vendor	Product	Versions
Gstreamer	Gstreamer	-
Redhat	Enterprise Linux	8.0

Related Weaknesses (CWE)

CWE-125

References

https://access.redhat.com/security/cve/CVE-2026-12891Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2491318Third Party Advisory
https://gitlab.freedesktop.org/gstreamer/gstreamer/-/work_items/5109Not Applicable

FAQ

What is CVE-2026-12891?

CVE-2026-12891 is a vulnerability with a CVSS score of 4.3 (MEDIUM). A flaw was found in the GStreamer gst-plugins-bad package. When processing a malformed H.266/VVC video stream with a crafted aspect ratio indicator value, the H.266 parser performs an out-of-bounds re...

How severe is CVE-2026-12891?

CVE-2026-12891 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-12891?

Check the references section above for vendor advisories and patch information. Affected products include: Gstreamer Gstreamer, Redhat Enterprise Linux.